We just upgraded to Pro V10 sp2, and since that upgrade shoppers are receiving the follow error when clicking on "continue checkout":
This website is using a scripted window to ask you for information. If you trust this website, click here to allow scripted windows...
After testing a variety of scenarios, it appears to only happen when the shipping zip code is left blank prior to clicking the checkout button, but it confusing a ton of customers.
We are testing with IE8, Paypal is activated in checkout as well.